Air Temperature and Precipitation

This section will focus on local and regional air temperature and precipitation patterns, and compare these values to historical conditions. The winter season was generally cooler than average (as is common during La Nina seasons), and saw near-normal precipitation and snowpack levels. Conditions changed abruptly near the end of April. This spring and summer have been warm (or hot) and exceptionally dry.

The maps below show monthly temperature anomalies and percent of normal precipitation for Western Canada in May, June, and July. Warm and dry conditions are a common theme for most of British Columbia for the past few months. The local temperature anomalies are not captured as well in this product, so we’ll look a little more closely at watershed conditions below.

Fig. 5 May-June-July Temperature Anomalies for Western Canada

Fig. 6 May-June-July Percent of Normal Precipitation for Western Canada

The table below shows monthly air temperature and precipitation data for the Lower Capilano Watershed. May is certainly a standout month with average temperatures almost 4 degrees warmer than normal. Only 111 mm of rain has fallen since April 24th.

Month	Mean Temp (°C )	Temp Anomaly (°C )	Precip (mm)	Precip % Normal
January	3.5	+0.4	318	87
February	1.8	-1.0	333	145
March	4.2	-0.6	118	35
April	6.2	-1.2	315	159
May	15.4	+3.7	19	15
June	16.5	+1.3	48	45
July	19.4	+1.8	44	96

Air Temperatures

The plot below shows the average daily temperature for 2023 (red line) compared to normals (gray shaded area) and the range of max and min (blue shaded area). New high and low temperature records are also plotted with red and blue dots. The sudden change in temperatures at the end of April is very clear. Nine new daily temperature records were set in May alone.

Hottest Day of the year

The hottest recorded temperature so far this year was on May 15th. The daytime high reached 32.7 degrees in the lower Capilano Watershed

Precipitation

The plot below shows the accumulated precipitation in the Lower Capilano Watershed in 2023. Last year is also shown in dark blue, and other years between 2003 and 2021 are shown with lighter shades of blue. Average annual accumulated precipitation is shown with the black dashed line.

The winter was marked by near normal precipitation, with the heaviest rain in February and the first half of April. It has been exceptionally dry since late April. Only 111 mm of rain has fallen since April 24. On average, the lower Capilano Watershed typically sees around 280 mm of rain in May-June-July.

We’ll take a closer look at drought in the next section.

Dry Spells!

33 days (May 7 - June 9), and 25 days (June 23 - July 18)

Note: Only 0.5 mm of rain fell in 32 days between June 22 and July 24